Beware buying new GM Rockers
#3
Melting Slicks
my guess is thats the tiny needle bearings making that noise. get yourself a BTR trunion or Straub kit and swap out them on your old rockers and return the rockers you bought from the dealer.
#4
Burning Brakes
Thread Starter
I have a CHE trunnion kit already. Gonna swap out the bad rocker with this one and use the currently installed trunnion from CHE.
I just wanted to know if its normal to be that loose. Its a brand new rocker...
I just wanted to know if its normal to be that loose. Its a brand new rocker...
#6
Team Owner
I would say so, since after I installed the Straub bushings in my engine, it got notably quieter.
#7
Melting Slicks
I'm curious why this is a 'Beware buying new GM Rockers' issue if we don't know whether it's normal or not? I assume the needles have some lubricant from manufacture, but aren't as flooded as they will be during operation.
#8
Safety Car
That is normal. There is a little bit of play in the needles. Soak in some oil and you won't hear anything.
Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure
But manufactures sure have made a ****-load of money off this myth.
Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure
But manufactures sure have made a ****-load of money off this myth.
#9
Melting Slicks
It does seem strange that GM would use what would intuitively seem a more expensive bearing methodology. That said, I have seen other applications where needle bearings in short oscillating rotations, such as a rocker arm, quickly wore on the shaft (or trunion). Full rotation would spread the wear better, but that's not how rockers work. I do note that small displacement, high RPM motorcycle engines have switched con rod bearings from needle to shell bearings, reportedly because a properly lubricated shell bearing has less friction than a needle bearing.
#10
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I would say its normal. No lube in the needle bearing.
Last edited by Bill Curlee; 10-15-2018 at 12:17 PM.
#11
Team Owner
It does seem strange that GM would use what would intuitively seem a more expensive bearing methodology. That said, I have seen other applications where needle bearings in short oscillating rotations, such as a rocker arm, quickly wore on the shaft (or trunion). Full rotation would spread the wear better, but that's not how rockers work. I do note that small displacement, high RPM motorcycle engines have switched con rod bearings from needle to shell bearings, reportedly because a properly lubricated shell bearing has less friction than a needle bearing.
#12
Burning Brakes
Thread Starter
I agree with the above. I wasn't sure if it was normal, and just wanted to to share my observations. I went with the CHE trunnion upgrade as it look to be a good upgrade and choice of company.
#13
That is normal. There is a little bit of play in the needles. Soak in some oil and you won't hear anything.
Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure
But manufactures sure have made a ****-load of money off this myth.
Also, IMHO that whole GM rocker needle bearing failure that everyone is so afraid of is a bunch of bull. I have NEVER seen or heard of a GM rocker bearing failure all by itself. Usually, the only reason the needles come loose is when there is some other significant failure
But manufactures sure have made a ****-load of money off this myth.
The following users liked this post:
ArmchairArchitect (10-15-2018)
#15
Drifting
This 100%. There is so much FUD (Fear, Uncertainty, and Doubt) spread about the GM rockers by aftermarket companies looking to make a buck, selling their products as preventative maintenance to guys with stock or small aftermarket cams. You'll never prove to me that any of the aftermarket rocker trunnion bearing or bushing kits are more durable or reliable than GM's in stock/small cam cars. The only reason I can see to run an aftermarket rocker setup is with a big cam and stiff springs, in which case you'll be doing regular valvetrain maintenance at much shorter intervals anyway.
#16
Actually there is LOTS of documentation on LS1.com of failures. This usually is not issue with a stock engine.... but stiffer valve springs and more aggressive camshafts make this problem come to the surface. when I bought my car... I spoke to my old neighbor about it (Kurt Urban..... yeah THAT Kurt Urban) he told me to do it and get rid of the "yellow springs" just for peace of mind since I pulled one of my heads to fix a cross threaded sparkplug the previous owner failed to mention LOL!
Just out of curiosity, which rocker trunnion kit did Kurt recommend / you install?
#18
Drifting
He dident.... just said a trunnion kit.... I got smith bros..... its not like I'm running endurance racing... I have a set of PAC 1218 beehives to get rid of the yellows... I just like my junk to be bulletproof even if its just to get me to work and back 90% of the time.
#19
Team Owner
#20
Drifting
I pull mine every two years and check:
- free length
- load at seated length
- load at open length
- excessive tilt at either end
- inspect coil for cracking
I go overboard and check the inner and outer springs separately, and use an MTS universal testing machine to make the measurement.
- free length
- load at seated length
- load at open length
- excessive tilt at either end
- inspect coil for cracking
I go overboard and check the inner and outer springs separately, and use an MTS universal testing machine to make the measurement.